Vacuum-insulated stacking container for the temperature-controlled transport of food

ABSTRACT

The invention relates to a stacking container ( 1 ) for the temperature controlled transport of food, comprising an outer container ( 3 ) with an outer container base ( 31 ) and an outer container wall ( 32 ) which are connected together so as to form a receiving area ( 33 ) which is open on one side. The stacking container ( 1 ) additionally comprises an inner container ( 2 ) with an inner container base ( 21 ) and an inner container wall ( 22 ) which are connected together so as to form a container area ( 23 ) which is open on one side. The inner container wall ( 22 ) comprises an upper edge section ( 221 ), and the outer container base ( 31 ) comprises a lower edge section ( 311 ), said upper edge section and lower edge section being designed in a complementary manner in order to engage into each other when stacking containers ( 1 ) are stacked one over the other such that the outer container base ( 31 ) of an upper stacking container ( 1 ) in the stack forms a cover for a stacking container ( 1 ) arranged therebelow, and a vacuum insulating element ( 5 ) is arranged between the inner container wall ( 22 ) and the outer container wall ( 32 ) and between the inner container base ( 21 ) and the outer container base ( 31 ).

The invention relates to a vacuum-insulated stacking container for the temperature-controlled (e.g., refrigerated/cooled) transport of food according to the independent claim.

Stacking containers of this type are widely known from practice and are used, for example, in the handling of bread in bakeries in the form of plastic boxes for transport, but also for storage. These plastic boxes are stackable in a filled and in an unfilled state.

Such plastic boxes comprise a container wall, which on four sides thereof encloses a container bottom in an encircling fashion, thereby creating a container space that is open towards the top on one side and can be loaded with bread or the like.

In this regard, the open rim of the container wall and the bottom are each designed with an encircling edge which can engage into each another. In this way, the edge at the container bottom of an overlying plastic box can rest against the edge at the container wall of an underlying plastic box, so as to secure the stacked plastic boxes against slipping.

The problem associated with such plastic boxes is that their application is limited due to a lack of insulating properties. Specifically, due to the aspect that the transport goods are more and more frequently delivered to so-called chain bakeries in a temperature-controlled state, conventional plastic boxes without insulation cannot be used for transport by delivery vehicles without a cooling/refrigeration unit. Even in vehicles with an integrated cooling/refrigeration unit, a significantly increased temperature effect occurs during transfer to the store. In this context, there is a risk that food stored therein or transported food may experience excessive temperature fluctuations, rendering the same unusable or causing the same to spoil.

The problem of insufficient insulation in plastic boxes for the transport of food also arises during the transport of meat products. Here, the risk of inadequate cooling/refrigeration already exists during handling within the butchery. This problem is also applicable to many other areas of food handling.

A thermally insulating stacking container is shown in DE 20 2016 001 097 U1. In principle, the transport container described therein can be used for temperature-sensitive food (e.g., bread, meat products, fish, etc.). The transport container comprises a lower part consisting of an inner container and an outer container, between which an insulating material is disposed. A closable lid is arranged on the lower part, the upper side of which, in the closed state, is complementary to the lower side of the transport container, so as to enable stacking. In contrast to the plastic boxes described above, the transport container is equipped with a lid, so that during stacking the lower side of the upper container is placed onto the closed lid. This results in principle in redundant insulation in the vertical direction, which is not required for normal food transport applications.

It is the object of the present invention to provide a stacking container which overcomes the disadvantages in the prior art and which, in particular, is of a simple design and enables convenient handling for transport.

This object is achieved by a stacking container for the temperature-controlled transport of food according to the independent claim. Advantageous embodiments constitute the subject-matter of the respective subclairns.

The present invention encompasses (vacuum-insulated) stacking containers for the temperature-controlled transport of food. The stacking container has an outer container with an outer container bottom and an outer container wall, which are connected together so as to form a receiving space which is open on one side. The stacking container further has an inner container with an inner container bottom and an inner container wail which are connected together so as to form a container space which is open on one side. The inner container wall has an upper rim section, and the outer container bottom has a lower rim section, which are designed in a complementary fashion so as to engage into each other when stacking containers are stacked one over the other. A vacuum insulation element is arranged between the inner container wall and the outer container wall and between the inner container bottom and the outer container bottom. Due to the design of the upper rim section, the lower rim section of the overlying stacking container can engage securely such that a plurality of stacking containers can be stacked securely one over the other. As a result of the arrangement of the vacuum insulation element between the inner container bottom and the outer container bottom, an insulated lid is provided when stacking containers are stacked by means of the bottom of the upper container terminating the container space of the lower container. Preferably, the vacuum insulation element is a vacuum insulation panel (VIP) described, for example, in EP 2 700 891 A2 or DE 20 2014 004 515 U1. In this way, a stacking container system consisting of at least two stacking containers arranged one above the other can be provided, wherein the outer bottom of an upper stacking container terminates the upper side of the container space of the lower stacking container. This results in highly insulated, stackable compartments that provide a thermal system with good thermal conductances less than 0.5 W/K. This corresponds to a heat transfer coefficient (U value) of approx. 0.61 W/(m² K) (inclusive of all thermal bridges, including the lid surface and based on the outer surface). As a rule, the temperature holding time achieved due to the very good insulation provided by the vacuum insulation elements is sufficient to achieve transport times of approx. 6 hours. In order to achieve extended transport times, e.q., up to 24 hours, phase change materials (PGM) can be introduced, which extend the temperature holding time accordingly, In order to prevent mechanical stress acting on the goods, the (PCM) accumulators (sides and/or lids) are fixed in the inliner by means of a holder and are prevented from falling over. As a termination of a stack of boxes or in the case that individual boxes are delivered or have a longer waiting time after delivery, an additional lid can be arranged, which comprises a vacuum insulation element.

According to an advantageous aspect, the inner container wall at the upper rim section and the outer container bottom at the lower rim section each comprise an L-shaped stop. The L-shaped design allows the upper rim section and the lower rim section to be simply designed in a complementary fashion so that the same are arrested in place in a slip-resistant fashion.

Advantageously, the L-shaped stop at the upper rim section and at the lower rim section each has a first profile section and (arranged at a right angle thereto) a second profile section, each with a minimum length of 0.5 cm.

Particularly preferably, the inner container wall comprises a projection completely encircling an upper rim section and having a size and shape such that, in the inserted state, the projection covers the outer container wall at least in sections.

Advantageously, the projection of the inner container wall is fixedly connected in an encircling fashion to the outer container wall.

In order to realize said fixed connection, the projection of the inner container and the outer container wall is preferably made of a thermally joinable plastic material. The plastic material may include, for example, polyurethane, polypropylene, or polyethylene. in this context, the projection of the inner container is welded to the outer container wall.

According to an alternative, the projection of the inner container is bonded to the outer container wall. According to the alternative, both thermally joinable and non-joinable materials can be joined by bonding.

It is further preferred that the inner wall, starting from the inner bottom, is arranged in a vertically tapering or a conically diverging fashion. Specifically, if the vacuum insulation element is a one-piece vacuum insulation panel that is folded according to the course of the inner container bottom and the outer container bottom, respectively, it is advantageous for assembly if the distance between the inner container bottom and the outer container bottom is larger while the distance between the inner container wall and the outer container wall is smaller.

According to a further advantageous aspect, the size of the inner container bottom surface is at least 70% of the size of the outer container bottom surface. Due to the excellent insulating properties of vacuum insulation panels, it is possible to keep the space between the inner container bottom surface and the outer container bottom surface small, so that a similarly large inner container bottom surface is provided compared to the outer container bottom surface.

It is particularly preferred that the vacuum insulation element is a single (one-piece) vacuum insulation panel. The vacuum insulation panel comprises at least one folded edge.

Advantageously, the outer container bottom has a size and shape so as to terminate in a completely encircling fashion the upper rim section of an underlying stacking container. According to one advantageous example, the termination between the containers is configured so as to inhibit convection.

One possible embodiment of this aspect provides that the outer container bottom has a sufficient height offset in the bottom structure to engage, in the stacked state of two stacking containers, into the underlying upper rim section to such a depth that the thermal path of heat is sufficiently extended as well as convection is reduced,

In the following, the invention will be explained in greater detail with reference to the examples shown in the accompanying drawings, wherein;

FIG. 1 is a detailed perspective view of the outer container and the inner container according to an exemplary embodiment of the stacking container according to the invention for the temperature-controlled transport of food;

FIG. 2 is a lateral cross-sectional view of the stacking container;

FIG. 3 is a detailed perspective view of a corner of an inner container from FIG. 1;

FIG. 4a is a perspective lateral view of two stacking containers being stacked one over the other;

FIG. 4b is a perspective lateral view of two stacking containers being stacked one over the other with a lid; and

FIG. 5 is a top view of a vacuum insulation element for a stacking container, as it can be arranged between the outer container and the inner container from FIG. 1.

In FIG. 1, a detailed view of the outer container 3 and the inner container 2 according to an exemplary embodiment of the stacking container 1 according to the invention is shown.

The outer container 3 comprises an outer container bottom 31 and an outer container wall 32 extending upwardly from the same. The outer container wall 32 and the outer container bottom 31 are formed from one piece and are respectively molded from a plastic material in one manufacturing step, The outer container 3 formed in this way has an upwardly open receiving space 33 on one side, into which the inner container 2 can be inserted almost entirely, so that a completely closed receiving space for a vacuum insulation element is created between the inside of the outer container 3 and the outside of the inner container 2.

The inner container 2 has an inner container bottom 21 and an inner container wall 22, which, being formed from one single material, are connected together, Thus, a container space 23 is formed, which is open on one side and which is suitable for accommodating food being intended for the temperature-controlled transport.

In order to provide stacking in a secure and stable manner, the inner container wall 22 has a rim section 221 at the top thereof with a completely encircling L-shaped stop.

The outer container bottom 31 has a lower rim section (not visible in this perspective view cf. FIG. 2), which is designed in a complementary fashion such that, when the stacking containers 1 are stacked one over the other, it rests against the L-shaped stop at the upper rim section 221 at the inner container wall 22 of the underlying stacking container 1.

The fully assembled stacking container for the temperature-controlled transport of food is shown in FIG. 2 in a lateral cross-sectional view.

In the cross-sectional view of the stacking container 1, the outer container 3 with an outer container bottom 31 and an outer container wall 32, which are directly connected together, can be seen. The inner container 2 is arranged in the upwardly open receiving space 33.

The inner container 2 has an inner container bottom 21 and an inner container wall 22, which are likewise directly connected.

From the cross-sectional view, the encircling upper rim section 221 with the L-shaped stop and the lower L-shaped stop arranged at the lower rim section 311 can be seen. The two L-shaped stop are designed in a complementary fashion such that, in the stacked state of two stacking containers 1, they lie one inside the other so as to secure the stacking containers 1 against slipping. The shown L-shaped stop at the lower rim section 311 has a first profile section 3111 with a length of 1.9 cm and a second profile section 3112 with a length of 0.8 cm.

In the upper region, the inner container wall 22 has a projection 222 completely encircling the upper rim section 221. The projection 222 has a size and shape being sufficient to completely cover the outer container wall 32 from above. in principle, the covering may also be formed in an incomplete fashion. This variant possibly results in disadvantages with regard to mechanical stability or thermal bridges.

The inner wall 22, starting from the inner bottom 21, is arranged in a conically diverging fashion, i.e., extending towards the outer container wall 32. The degree of conicity can vary depending on the production technology and the application. As a rule, a minimum of about 1° is considered appropriate.

The vacuum insulation element 5 shown is a one-piece vacuum insulation panel.

FIG. 3 is a detailed perspective view of a corner of an inner container of the stacking container of FIG. 2.

The inner container wall 22 has an upper rim section 221 with an L-shaped stop and an encircling projection adjoining thereto. The width of the projection 222 corresponds to the thickness of the outer container wall. The shown L-shaped stop at the upper rim section 221 in each case has a first profile section 2211 with a length of 1.3 cm and a second profile section 2212 with a length of 0.8 cm.

In FIG. 4a , a stack consisting of two stacking containers is shown. In the upper stacking container 1, the outer container bottom (not shown) is designed to rest against the upper rim section of the lower stacking container. In FIG. 4b , the stack is shown with an insulated lid 6, wherein the lid 6 at the upper side thereof comprises a profile which is complementary to the lower side of the outer container.

The vacuum insulation panel 5 shown in FIG. 5 has four folding edges 51, each of which, in the installed state, being arranged along the outer periphery of the outer container bottom. The contour of the wings 52 is created to fit to the outer and inner container (e.g., conicity). If geometry (e.g., conicity) is negligible, the contour simplifies accordingly. 

1. Stacking container for the temperature-controlled transport of food, comprising an outer container with an outer container bottom and an outer container wall, which are connected together so as to form a receiving space which is open on one side, and wherein the stacking container additionally comprises an inner container with an inner container bottom and an inner container wall which are connected together so as to form a container space which is open on one side, wherein the inner container wall comprises an upper rim section, and the outer container bottom comprises a lower rim section which are designed in a complementary fashion so as to engage into each other when stacking containers are stacked one over the other such that the outer container bottom of an overlying stacking container in the stack forms a lid for a stacking container arranged therebelow, and wherein a vacuum insulation element is arranged between the inner container wall and the outer container wall and between the inner container bottom and the outer container bottom.
 2. Stacking container according to claim 1, wherein the inner container wall at the upper rim section and the outer container bottom at the lower rim section each comprise an L-shaped stop.
 3. Stacking container according to claim 2, wherein the L-shaped stop at the upper rim section and the lower rim section each comprises a first profile section and a second profile section each having a minimum length of 0.5 cm.
 4. Stacking container according to claim 1, wherein the inner container wall comprises a projection completely encircling the upper rim section and having a size and shape such that, in the inserted state, the projection covers the outer container wall at least in sections.
 5. Stacking container according to claim 4, wherein the projection of the inner container is fixedly connected in an encircling fashion to the outer container wall.
 6. Stacking container according to claim 4, wherein the projection of the inner container and the outer container wall are made of a thermally joinable plastic material, and wherein the projection of the inner container is welded to the outer container wall.
 7. Stacking container according to claim 4, wherein the projection of the inner container is bonded to the outer container wall.
 8. Stacking container according to claim 4, wherein the projection of the inner container is detachably connected in an encircling fashion to the outer container wall.
 9. Stacking container according to claim 1, wherein the inner wall, starting from the inner bottom, is arranged in a vertically tapering fashion or in a conically diverging fashion.
 10. Stacking container according to claim 1, wherein the size of the inner container bottom surface is at least 70% of the size of the outer container bottom surface.
 11. Stacking container according to claim 1, wherein the vacuum insulation element is a single vacuum insulation panel, and wherein the vacuum insulation panel comprises at least one folding edge.
 12. Stacking container according to claim 11, wherein the vacuum insulation panel comprises four folding edges, and wherein said four folding edges, in the installed state, are each arranged along the outer periphery of the outer container bottom.
 13. Stacking container according to claim 1, wherein the outer container bottom has a size and shape so as to terminate in a completely encircling fashion the upper rim section. 